Changeset 11534
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 20190911T15:38:28+02:00 (3 years ago)
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NEMO/branches/2019/dev_r10984_HPC13_IRRMANN_BDY_optimization/doc/latex/NEMO/subfiles/chap_LBC.tex
r11531 r11534 113 113 \begin{description} 114 114 115 \item[freeslip boundary condition (\np{rn\_shlat}\forcode{ =0}):] the tangential velocity at115 \item[freeslip boundary condition (\np{rn\_shlat}\forcode{=0}):] the tangential velocity at 116 116 the coastline is equal to the offshore velocity, 117 117 \ie\ the normal derivative of the tangential velocity is zero at the coast, … … 119 119 (\autoref{fig:LBC_shlat}a). 120 120 121 \item[noslip boundary condition (\np{rn\_shlat}\forcode{ =2}):] the tangential velocity vanishes at the coastline.121 \item[noslip boundary condition (\np{rn\_shlat}\forcode{=2}):] the tangential velocity vanishes at the coastline. 122 122 Assuming that the tangential velocity decreases linearly from 123 123 the closest ocean velocity grid point to the coastline, … … 361 361 % 362 362 363 Options are defined through the \nam{bdy} \nam{bdy\_dta} namelist variables.363 Options are defined through the \nam{bdy} and \nam{bdy\_dta} namelist variables. 364 364 The BDY module is the core implementation of open boundary conditions for regional configurations on 365 365 ocean temperature, salinity, barotropicbaroclinic velocities, icesnow concentration, thicknesses, temperatures, salinity and melt ponds concentration and thickness. … … 376 376 \label{subsec:BDY_namelist} 377 377 378 The BDY module is activated by setting \np{ln\_bdy}\forcode{ =.true.} .378 The BDY module is activated by setting \np{ln\_bdy}\forcode{=.true.} . 379 379 It is possible to define more than one boundary ``set'' and apply different boundary conditions to each set. 380 380 The number of boundary sets is defined by \np{nb\_bdy}. 381 381 Each boundary set can be either defined as a series of straight line segments directly in the namelist 382 (\np{ln\_coords\_file}\forcode{ = .false.}, and a namelist block \nam{bdy\_index} must be included for each set) or read in from a file (\np{ln\_coords\_file}\forcode{ =.true.}, and a ``\ifile{coordinates.bdy}'' file must be provided).382 (\np{ln\_coords\_file}\forcode{=.false.}, and a namelist block \nam{bdy\_index} must be included for each set) or read in from a file (\np{ln\_coords\_file}\forcode{=.true.}, and a ``\ifile{coordinates.bdy}'' file must be provided). 383 383 The coordinates.bdy file is analagous to the usual \NEMO\ ``\ifile{coordinates}'' file. 384 384 In the example above, there are two boundary sets, the first of which is defined via a file and … … 389 389 (``u2d'':seasurface height and barotropic velocities), for the baroclinic velocities (``u3d''), 390 390 for the active tracers \footnote{The BDY module does not deal with passive tracers at this version} (``tra''), and for seaice (``ice''). 391 For each set of variables one has to choose an algorithm and the boundary data (set resp. by \np{cn\_tra} and \np{ cn\_tra} for tracers).\\391 For each set of variables one has to choose an algorithm and the boundary data (set resp. by \np{cn\_tra} and \np{nn\_tra\_dta} for tracers).\\ 392 392 393 393 The choice of algorithm is currently as follows: … … 405 405 406 406 The boundary data is either set to initial conditions 407 (\np{nn\_tra\_dta}\forcode{ = 0}) or forced with external data from a file (\np{nn\_tra\_dta}\forcode{ =1}).407 (\np{nn\_tra\_dta}\forcode{=0}) or forced with external data from a file (\np{nn\_tra\_dta}\forcode{=1}). 408 408 In case the 3d velocity data contain the total velocity (ie, baroclinic and barotropic velocity), 409 the bdy code can derived baroclinic and barotropic velocities by setting \np{ln\_full\_vel}\forcode{ = .true.}409 the bdy code can derived baroclinic and barotropic velocities by setting \np{ln\_full\_vel}\forcode{=.true.} 410 410 For the barotropic solution there is also the option to use tidal harmonic forcing either by 411 itself (\np{nn\_dyn2d\_dta}\forcode{ = 2}) or in addition to other external data (\np{nn\_dyn2d\_dta}\forcode{ =3}).\\411 itself (\np{nn\_dyn2d\_dta}\forcode{=2}) or in addition to other external data (\np{nn\_dyn2d\_dta}\forcode{=3}).\\ 412 412 If not set to initial conditions, seaice salinity, temperatures and melt ponds data at the boundary can either be read in a file or defined as constant (by \np{rn\_ice\_sal}, \np{rn\_ice\_tem}, \np{rn\_ice\_apnd}, \np{rn\_ice\_hpnd}). Ice age is constant and defined by \np{rn\_ice\_age}. 413 413 … … 424 424 425 425 There is currently an option to vertically interpolate the open boundary data onto the native grid at runtime. 426 If \np{nn\_bdy\_jpk} $<1$, it is assumed that the lateral boundary data are already on the native grid.426 If \np{nn\_bdy\_jpk}$<1$, it is assumed that the lateral boundary data are already on the native grid. 427 427 However, if \np{nn\_bdy\_jpk} is set to the number of vertical levels present in the boundary data, 428 428 a bilinear interpolation onto the native grid will be triggered at runtime. … … 583 583 \jp{jpinft} give the start and end $i$ indices for each segment with similar for the other boundaries. 584 584 These segments define a list of $T$ grid points along the outermost row of the boundary ($nbr\,=\, 1$). 585 The code deduces the $U$ and $V$ points and also the points for $nbr\,>\, 1$ if \np{nn\_rimwidth}\forcode{ >1}.585 The code deduces the $U$ and $V$ points and also the points for $nbr\,>\, 1$ if \np{nn\_rimwidth}\forcode{>1}. 586 586 587 587 The boundary geometry may also be defined from a ``\ifile{coordinates.bdy}'' file. … … 659 659 There is an option to force the total volume in the regional model to be constant. 660 660 This is controlled by the \np{ln\_vol} parameter in the namelist. 661 A value of \np{ln\_vol}\forcode{ =.false.} indicates that this option is not used.661 A value of \np{ln\_vol}\forcode{=.false.} indicates that this option is not used. 662 662 Two options to control the volume are available (\np{nn\_volctl}). 663 If \np{nn\_volctl}\forcode{ =0} then a correction is applied to the normal barotropic velocities around the boundary at663 If \np{nn\_volctl}\forcode{=0} then a correction is applied to the normal barotropic velocities around the boundary at 664 664 each timestep to ensure that the integrated volume flow through the boundary is zero. 665 If \np{nn\_volctl}\forcode{ =1} then the calculation of the volume change on665 If \np{nn\_volctl}\forcode{=1} then the calculation of the volume change on 666 666 the timestep includes the change due to the freshwater flux across the surface and 667 667 the correction velocity corrects for this as well.
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